[PATCH 2/6] cacheinfo: Set cache 'id' based on DT data
From: Rob Herring <robh@kernel.org>
Date: 2021-12-16 23:31:37
Also in:
linux-acpi, linux-devicetree, lkml
Subsystem:
driver core, kobjects, debugfs and sysfs, the rest · Maintainers:
Greg Kroah-Hartman, "Rafael J. Wysocki", Danilo Krummrich, Linus Torvalds
Use the minimum CPU h/w id of the CPUs associated with the cache for the cache 'id'. This will provide a stable id value for a given system. As we need to check all possible CPUs, we can't use the shared_cpu_map which is just online CPUs. There's not a cache to CPUs mapping in DT, so we have to walk all CPU nodes and then walk cache levels. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Signed-off-by: Rob Herring <robh@kernel.org> --- v2: - Loop with for_each_possible_cpu instead of for_each_of_cpu_node as we will need the logical cpu numbers. --- drivers/base/cacheinfo.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+)
diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c
index 66d10bdb863b..21accddf8f5f 100644
--- a/drivers/base/cacheinfo.c
+++ b/drivers/base/cacheinfo.c@@ -136,6 +136,36 @@ static bool cache_node_is_unified(struct cacheinfo *this_leaf, return of_property_read_bool(np, "cache-unified"); } +static void cache_of_set_id(struct cacheinfo *this_leaf, struct device_node *np) +{ + int cpu; + unsigned long min_id = ~0UL; + + for_each_possible_cpu(cpu) { + u64 id; + struct device_node *cache_node, *cpu_node; + + cache_node = cpu_node = of_get_cpu_node(cpu, NULL); + id = of_get_cpu_hwid(cpu_node, 0); + while ((cache_node = of_find_next_cache_node(cache_node))) { + if (cache_node == np) { + if (id < min_id) { + min_id = id; + of_node_put(cache_node); + break; + } + } + of_node_put(cache_node); + } + of_node_put(cpu_node); + } + + if (min_id != ~0UL) { + this_leaf->id = min_id; + this_leaf->attributes |= CACHE_ID; + } +} + static void cache_of_set_props(struct cacheinfo *this_leaf, struct device_node *np) {
@@ -151,6 +181,7 @@ static void cache_of_set_props(struct cacheinfo *this_leaf, cache_get_line_size(this_leaf, np); cache_nr_sets(this_leaf, np); cache_associativity(this_leaf); + cache_of_set_id(this_leaf, np); } static int cache_setup_of_node(unsigned int cpu)
--
2.32.0
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